Lufang Jiang

Serological and virological surveillance of avian influenza A virus H9N2 subtype in humans and poultry in Shanghai, China, between 2008 and 2010.

We report the serological evidence of low‐pathogenic avian influenza (LPAI) H9N2 infection in an occupational poultry‐exposed population and a general population. A serological survey of an occupational poultry‐exposed population and a general population was conducted using a haemagglutinin‐inhibiting (HI) assay in Shanghai, China, from January 2008 to December 2010. Evidence of higher anti‐H9 antibodies was found in serum samples collected from poultry workers. During this period, 239 H9N2 avian influenza viruses (AIVs) were isolated from 9297 tracheal and cloacal paired specimens collected from the poultry in live poultry markets. In addition, a total of 733 influenza viruses were isolated from 1569 nasal and throat swabs collected from patients with influenza‐like symptoms in a sentinel hospital, which include H3N2, H1N1, pandemic H1N1 and B, but no H9N2 virus was detected. These findings highlight the need for long‐term surveillance of avian influenza viruses in occupational poultry‐exposed workers.

The epidemiology of hospitalized influenza in children, a two year population-based study in the People's Republic of China.

BackgroundThe epidemiology and disease burden of annual influenza in children in mainland Peoples Republic of China have not been reported in detail. To understand the incidence and epidemiology of laboratory-proven influenza hospitalization in children in China, a review of available laboratory and hospital admission data was undertaken.MethodsWe conducted a retrospective population-based study in Suzhou and the surrounding area of Jiangsu province, China for hospitalized cases of respiratory illness at Suzhou Childrens Hospital. Cases of pneumonia or respiratory illness were identified from hospital computer data bases. Routine virological testing by fluorescent monoclonal antibody assay of all hospitalized children identified influenza and other viruses. We calculated incidence rates using census population denominators.ResultsOf 7,789 specimens obtained during 2007 and 2008, 85 were positive for influenza A and 25 for influenza B. There were 282 specimens with parainfluenza virus and 1392 with RSV. Influenza occurred throughout the year, with peaks in the winter, and in August/September. Overall estimated annual incidence of laboratory-proven influenza hospitalization was 23-27/100,000 children 0-4 years old, and 60/100,000 in infants 0-6 months, with an average hospitalization of 9 days.ConclusionsInfluenza disease in young children in this part of China is a relatively common cause of hospitalization, and occurs throughout the year. The use of influenza vaccine in Chinese children has the potential to reduce the effect of influenza in the children, as well as in their communities. Studies are needed to further assess the burden of influenza, and to develop and refine effective strategies of immunization of young children in China.

The complexity of human infected AIV H5N6 isolated from China

BackgroundNovel avian influenza viruses (AIVs) of H7N9, H10N8, and H5N6 are currently circulating in China’s poultry flocks, occasionally infecting human and other mammals. Human infected AIV H5N6 in China during 2014–2015 is believed to be a triple reassortant originated from H6N6 and two clades of H5 viruses. The current report suggests that its reassortment history is more complicated.MethodsGenomes of human infected isolates of AIV H5N6 were searched from the NCBI Influenza Virus Sequence Database and the Global Initiative on Sharing Avian Influenza Data. Sequences shared high identities with each segment of their genomes were obtained through the Basic Local Alignment Search Tool. Alignments were done by mafft-7.037-win32 program; 8 large-scale and then 8 gradually converged phylogenetic trees were constructed by using MEGA5.1/5.2/6.0 Software.ResultsThe events that each segment of the genomes of human infected AIV H5N6 isolates circulated in China had evolved into its current status might have happened before 2013, and so were they then reassorted into the epidemic AIV H5N6. A/Guangzhou/39715/2014(H5N6) and A/Sichuan/26221/2014(H5N6) had their six internal segments (PB2, PB1, PA, NP, NEP, and M) in common, and were reassorted from AIVs H5N1 in the same period and same region as that of HA, while A/Yunnan/0127/2015(H5N6) derived its six internal segments from AIV H9N2 that has been prevalent in Eastern China since 2008.ConclusionsAIV H5N6 isolates established from both human and poultry in China during 2014–2015 were heterogeneous; both AIVs H5N1 and H9N2 were involved in the reassortment of AIV H5N6 in China.

Co-infection with influenza A/H1N1 and A/H3N2 viruses in a patient with influenza-like illness during the winter/spring of 2008 in Shanghai, China

Co‐infection with different influenza viruses occurs naturally and plays an important role in epidemiology and pathogenicity. To monitor the prevalence of influenza viruses in humans during seasonal influenza epidemics in Shanghai, China, and to analyze the genetic characteristics of the viruses, 365 nasopharyngeal swabs collected from patients with influenza‐like illness between January and April 2008, were tested by a colloidal gold assay, viral isolation in Madin‐Darby canine kidney (MDCK) cells, direct immunofluorescence assay and multiplex RT‐PCR. The genetic characteristics of the viruses were analyzed by full‐length PCR amplification of the HA segment. One case of co‐infection with influenza A/H1N1 and A/H3N2 viruses was detected among the 7 cases of A/H1N1, 84 cases of A/H3N2 and 48 cases of influenza B virus during the winter/spring of 2008. All influenza A/H1N1 and A/H3N2 isolates were similar, including the co‐infecting isolates. The present study demonstrates the possibility of natural co‐infection with different types of influenza viruses in humans, which could provide the opportunity for the occurrence of viral genetic reassortment within the human respiratory tract. J. Med. Virol. 82:1299–1305, 2010.

Antigenic and genetic variation in the hemagglutinins of H1N1 and H3N2 human influenza a viruses in the Shanghai area from 2005 to 2008.

Continued rapid evolution of the influenza A virus is responsible for annual epidemics and occasional pandemics in the Shanghai area. In the present study, the representative strains of A/H1N1 and A/H3N2 influenza viruses isolated in the Shanghai area from 2005 to 2008 were antigenically and genetically characterized. The antigenic cartography method was carried out to visualize the hemagglutination‐inhibition data. Antigenic differences were detected between circulating A/H1N1 strains isolated from 2005 to 2006 and the epidemic A/H1N1 strains isolated in 2008, which were found to be associated with the amino acid substitution K140E in HA1. The present vaccine strain A/Brisbane/59/2007 is considered to be capable of providing sufficient immunity against most of the circulating A/H1N1 viruses isolated in 2008 from the Shanghai population. The study showed that there were significant antigenic differences between the epidemic A/H3N2 strains isolated in 2007 and 2008, suggesting that antigenic drift had occurred in the A/H3N2 strains isolated in 2008. The P194L mutation was thought to be responsible for the antigenic evolution of influenza A/H3N2 viruses isolated from Shanghai in 2008. Evidence of antigenic drift suggests that the influenza A/H3N2 vaccine component needs to be updated. J. Med. Virol. 83:1113–1120, 2011.

Effects of oral florfenicol and azithromycin on gut microbiota and adipogenesis in mice

Certain antibiotics detected in urine are associated with childhood obesity. In the current experimental study, we investigated two representative antibiotics detected in urine, florfenicol and azithromycin, for their early effects on adipogenesis, gut microbiota, short-chain fatty acids (SCFAs), and bile acids in mice. Thirty C57BL/6 mice aged four weeks were randomly divided into three groups (florfenicol, azithromycin and control). The two experimental groups were administered florfenicol or azithromycin at 5 mg/kg/day for four weeks. Body weight was measured weekly. The composition of the gut microbiota, body fat, SCFAs, and bile acids in colon contents were measured at the end of the experiment. The composition of the gut microbiota was determined by sequencing the bacterial 16S rRNA gene. The concentration of SCFAs and bile acids was determined using gas chromatography and liquid chromatography coupled to tandem mass spectrometry, respectively. The composition of the gut microbiota indicated that the two antibiotics altered the gut microbiota composition and decreased its richness and diversity. At the phylum level, the ratio of Firmicutes/Bacteroidetes increased significantly in the antibiotic groups. At the genus level, there were declines in Christensenella, Gordonibacter and Anaerotruncus in the florfenicol group, in Lactobacillus in the azithromycin group, and in Alistipes, Desulfovibrio, Parasutterella and Rikenella in both the antibiotic groups. The decrease in Rikenella in the azithromycin group was particularly noticeable. The concentration of SCFAs and secondary bile acids decreased in the colon, but the concentration of primary bile acids increased. These findings indicated that florfenicol and azithromycin increased adipogenesis and altered gut microbiota composition, SCFA production, and bile acid metabolism, suggesting that exposure to antibiotics might be one risk factor for childhood obesity. More studies are needed to investigate the specific mechanisms.

Could A Deletion in Neuraminidase Stalk Strengthen Human Tropism of the Novel Avian Influenza Virus H7N9 in China, 2013?

Objective. A novel avian influenza A virus (AIV) H7N9 subtype which emerged in China in 2013 caused worldwide concern. Deletion of amino-acids 69 to 73 in the neuraminidase stalk was its most notable characteristic. This study is aimed to discuss the tropism and virulence effects of this deletion. Methods: Neuraminidase gene sequences of N9 subtype were collected from NCBI and GISAID. MEGA6.0, Stata12.0, and UCSF Chimera were employed for sequence aligning, significance testing, and protein tertiary structure homology modeling. Results: A total of 736 sequences were obtained; there were 81 human isolates of the novel AIV H7N9, of which 79 had the deletion. Among all the 654 avian origin sequences, only 43 had the deletion (p < 0.001). Tertiary structure displayed that the deletion obviously changed the spatial direction of neuraminidase. Conclusions: The deletion in neuraminidase stalk could have strengthened human tropism of the novel AIV H7N9, as well as its virulence.

Avian influenza viruses (AIVs) H9N2 are in the course of reassorting into novel AIVs

中文概要目的分析H9N2 禽流感病毒通过基因重配形成H7N9 和H10N8 人间禽流感病毒的进程,探讨作为供体 的禽流感病毒H9N2 在当前中国的主要分布及其 内部6 个基因节段的进化关系。创新点人间禽流感病毒H7N9 和H10N8 共起源于H9N2 禽流感病毒早已成为共识,但共起源的时间节 点、作为供体的禽流感病毒H9N2 在当前中国的 分布及其内部6 个基因节段的进化关系鲜有论 及。2014 年,H5N6 禽流感被多次报道造成人类 感染。研究表明,H5N6 禽流感具有复杂的重配 来源,H9N2 正是其一,加之H7N9 第五波流行 的严峻形势,亟需明确H9N2 禽流感病毒通过基 因重配形成新亚型的能力以及它在我国的当前 主要分布。方法从流感病毒公共数据库下载基因序列,评估查找 适当的碱基替代模型,通过进化树查看与H7N9、 H10N8 及H5N6 具有高度相似性的H9N2 病毒的 分布地区以及它们在内部6 个基因节段上的进化 关系,同时通过碱基替代速率的计算追溯最近共 同祖先(tMRCA)及其分歧时间。结论人间禽流感病毒H7N9 与H10N8 均在2012 年之 前形成,短期内通过碱基替代与基因重配形成了 两种可感染人类的禽流感病毒,证实了H9N2 通 过重配形成新亚型的高效性。作为重配供体的 H9N2 至今仍广布于华东、华南及东南亚。其内 部基因节段的重配复杂,发生在亚型内部的重配 以及通过重配形成新的病毒亚型的风险都很高, 需在禽畜中加强流感病毒的流行动态监测,特别 是那些一向被忽视的编码内部蛋白的基因组节 段。

Additional file 1: of The complexity of human infected AIV H5N6 isolated from China

1aâ 8a: Matrices of genomes involved in this study. 1a, PB2 (fas 4.73mb); 2a, PB1 (fas 4.72mb); 3a, PA (fas 4.45mb); 4a, HA (fas 1.88mb); 5a, NP (fas 3.26mb); 6a, NA (fas 1.62mb); 7a, MP (fas 2.33mb); 8a, NEP (fas 1.99mb). (ZIP 1 mb)

Biological Characteristics of H9N2 Avian Influenza Viruses from Healthy Chickens in Shanghai, China

Background H9N2 avian influenza viruses that circulate in domestic poultry in eastern China pose challenges to human health. However, few studies have compared the biological characteristics of H9N2 viruses isolated from healthy chickens in Shanghai. Material/Methods Three H9N2 viruses – CK/SH/Y1/07, CK/SH/Y1/02, and CK/SH/23/13 – isolated from healthy chickens in Shanghai between 2002 and 2013, were selected and their biological characteristics were determined. Results All 3 H9N2 viruses showed a preference for both the avian- and human-like receptors, and they replicated well in MDCK and A549 cells. All H9N2 viruses were non-pathogenic to mini-pigs and were detected in the trachea and lung tissues. The CK/SH/Y1/07 and CK/SH/Y1/02 viruses were transmitted to mini-pigs through direct-contact or respiratory droplet exposure, but CK/SH/23/13 virus was not. Conclusions These results suggest that H9N2 viruses isolated from healthy chickens in Shanghai efficiently replicate and transmit among pigs and other mammals.